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Mark Henley
Mark Henley, Journeyman Technician
Category: HVAC
Satisfied Customers: 3217
Experience:  UA Journeyman Pipefitter , HVAC, Refrigeration, DDC controls. 26 years.Commercial & residential
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I have a White Rodgers Thermostat 1f79 trying to install color

Customer Question

I have a White Rodgers Thermostat 1f79 trying to install color coded wires to my goodman heat pump with back up electric!
Submitted: 5 years ago.
Category: HVAC
Expert:  Mark Henley replied 5 years ago.

Could you explain the situation a little more, is this an existing unit and you are changing the stat or something else ?

JACUSTOMER-eing9okl- :
This is the stat that was first installed with the unit, however, because the installer did such a poor job and our heat pump was costing us a fortune to run, over 600 dollars a month in the winter, I unhooked it and replaced it with a honeywell direct to the furnace without running our heat pump. I did not write down my color codes for the wires so that I could reinstall it for air conditioning

Mark Henley :
Can you tell me which wire colors you have, I can give you the typical connections for them , though there is no way I can verify if they are correct if someone initially used the wrong colors , they will usually use the correct ones though.

JACUSTOMER-eing9okl- :
I have Red, Orange, Black, Brown, Green, White, Yellow , Blue coming out of the wall. The problem is this thermostat is not so easy to tell what wire goes where because it has the following hook ups. W2, E, OB, R, L, G, C , how the hell I am supposed to figure that out is beyond me

Mark Henley :
Here are the wire connections:
Red, R and jump to RH or RC all the R teminals go together
Orange, OB
Black, = E
Brown, = L
Green, = g
White, = W2
Yellow = Y
Blue = C

This is typical but if you get the common wire wrong it will ruin the transformer in the unit, if you can get to the indoor unit and figure out which wire is on that C terminal it will help,

JACUSTOMER-eing9okl- :
The strange thing is that I remember when I unhooked this the first time the black wire was not even used for some reason. I am not sure why

The electric furnace is not indoors, it is under the house, just my luck

Mark Henley :
Leave it off, that is not uncommon for the emergency heat to not be connected. Do you happen to remember which wire was on C ?

JACUSTOMER-eing9okl- :
no, but I do remember that the emergency heat worked

Mark Henley :
ok it will be the blue one or the brown one, blue usually but could be the brown one. Was there a jumper between W2 and E ? that is how it is doen a lot

JACUSTOMER-eing9okl- :
so blue or brown to C?
no jumpers of any kind

Mark Henley :
yes blue or brown, if the stat has batteies in it you can just leave both of those off and it should run,
the L doesn't need to be connected

JACUSTOMER-eing9okl- :
the stat does have batteries, and which ones can I leave off?

Mark Henley :
brown and blue, and black

JACUSTOMER-eing9okl- :
so I can leave off C, L, and E as long as I use batteries

Mark Henley :
Yes E was emergency heat , you don't need it for cooling and you can jump W2 to E and get the same effect if you want that to work, and C is 24 Volt common you don't need it if you use battery power, and L is a terminal to light a Lamp it's not necessary.You can reconnect these if you want to after you sort them out at the air handler.